energetics (paper 2) 55, 58

Question 1

what do reaction profiles show

Answer 1

the relative energies of the reactants and products in a reaction and how the energy changes over the course of the reaction

Question 2

describe what an exothermic energy profile looks like

Answer 2

• the reactants line is higher than the products
• draw a loop/arch very from the reactants and products line
• an arrow going from the reactants to the top of the loop/arch to show activation energy
• an arrow going from the reactants to the products to show ΔH

Question 3

describe what an endothermic energy profile looks like

Answer 3

• the reactants line is lower than the products
• draw a loop/arch going above the line for products and thenn connecting
• an arrow going from the reactants to the top of the loop/arch to show activation energy
• a line going up from reactants to products to show ΔH

Question 4

what can bond energy calculatios be used for

Answer 4

to calculate the energy change that occurs during a reaction

Question 5

what is meant by the term bond energy

Answer 5

the amount of energy required to break 1 mole of a particular covalent bond

Question 6

what is the calculation for bond energy

Answer 6

ΔH = reactant bonds - products bonds